Multiple-Input-Multiple-Output (mimo) Communication

1. A method of controlling a plurality of streams of a multiple-input-multiple-output wireless telecommunication network, said method comprising: determining whether an amount of data available for transmission that is greater than a maximum capacity of one of said plurality of streams is below a threshold capacity of at least another of said plurality of streams; and if so, reducing a rank of transmission by preventing transmission of at least one of said plurality of streams; wherein the rank of transmission is reduced by 1 when an amount of data carried by any of the streams is supportable by a code configuration which provides a lower capacity than a maximum capacity code configuration for that stream.

2. The method of claim 1 , wherein said at least one of said plurality of streams which is prevented is said another of said plurality.

3. The method of claim 1 , wherein said at least one of said plurality of streams which is prevented is other than said another of said plurality.

4. The method of claim 1 , wherein said at least one of said plurality of streams is any of said plurality of streams.

5. The method of claim 1 , wherein each of said plurality of streams has a respective threshold capacity.

6. The method of claim 1 , wherein each of said plurality of streams is configurable to support data transmission with a plurality of different data capacities, including a default data capacity and lower data capacities, and wherein said threshold capacity is one of said lower capacities.

7. The method of claim 6 , wherein said threshold capacity is a lower capacity which is closest to said default capacity.

8. The method of claim 6 , wherein said default capacity is a maximum capacity.

9. The method of claim 1 , comprising receiving an indication of each threshold capacity.

10. The method of claim 6 , wherein each of said plurality of different data capacities is achieved using a corresponding one of a plurality of different spreading code configurations for data transmissions over said streams.

11. The method of claim 1 , comprising receiving an indication of a spreading code configuration which achieves each threshold capacity.

12. The method of claim 1 , wherein said threshold capacity is a maximum data capacity achieved using said spreading code configuration.

13. The method of claim 1 , wherein said plurality of streams comprise a primary stream and at least one secondary stream, and said determining comprises determining whether said amount of data for transmission over at least one secondary stream would fail to achieve said threshold capacity.

14. A non-transitory computer readable medium storing a computer program, which when executed on a computer, performs the method of claim 1 .

15. The method of claim 1 , wherein said plurality of streams are two streams.

16. User equipment operable to control a plurality of streams of a multiple-input-multiple-output wireless telecommunication network, said user equipment comprising: determination logic operable to determine whether an amount of data available for transmission that is greater than a maximum capacity of one of said plurality of streams is below a threshold capacity of at least another of said plurality of streams; and transmission logic operable, in response to said determination logic determining that said amount of data available for transmission is below said threshold capacity, to reduce a rank of transmission by preventing transmission of at least one of said plurality of streams; wherein the rank of transmission is reduced by 1 when an amount of data carried by any of the streams is supportable by a code configuration which provides a lower capacity than a maximum capacity code configuration for that stream.